These Are The 10 Biggest Real-Time Bidding Advertisers On The Web

AT&T is the biggest “real-time bidding” advertiser on the web, according to Rubicon Project, one of the largest RTB platforms in the U.S.

While publishers generally try to sell their ad space directly to advertisers in “premium” deals, a huge amount of ads are served as part of gigantic on online auctions, in which ads are placed automatically, based on supply and demand and pricing. RTB is a $2 billion business, according to ComScore.

Rubicon handles so much of this “real-time bidding” business that its reach — in terms of the percentage of Americans who see an ad served via Rubicon — is now larger than Google’s. About 96.9% of all Internet users in the U.S. see a Rubicon ad in any given month.

Rubicon serves about one third of the top 500 web sites, based on traffic measured by ComScore, the company says.

Here are Rubicon’s top clients:

Photo: Rubicon Project

The company declined to release dollar budgets accompanying the ranking. The data is drawn from 73 billion paid RTB impressions.

It’s not surprising that AT&T is the biggest RTB advertiser. It is also the biggest social media advertiser. (Zalando, in case you’re wondering, is a British shoe and fashion retailer.)

Rubicon also released this information about where the money is going: